Electric heater



May'27, 1930. l.. P. H'YNES 41,750,065

ELECTRI C HEATER Filed March 24, 192.4

lnventoz LEE P. HYN E5 @5% hns, @Miei/mug Law Patented May 27, 1930 UNITED STATES PATENT OFFICE LEE P. HYNES, OF ALBANY, NEW YORK, ASSIGNOR, BY MESNE ASSIGNMENTS, TO CON` SOLIDATED CAR-HEATIN G COMPANY, INC., OF ALBANY, NEW YORK, A CORPORATION OF NEW YORK ELECTRIC Application filed March 24,

For a detailed description of the present form of my invention, reference may be had to the i'ollowing specification and to the accompanying drawings, wherein :2S Fig. l is an end view of my heater with the casing-head removed and Fig. 2 a section through the casing and partly through one of the heater elements.

My invention relates to heaters of the Well Fifi known McElroy type wherein a coil of resisting wire is wound helically in a helical groove around a porcelain core. These are known as open or exposed-coil heaters in distinction from those having embedded coils.

In such heaters trouble is sometimes caused by a break in the heater-coil caused by accidental or undue concentration of heat at one point which fuses the wire at that point. In that event the coil nnwinds from its core and comes in `contact with the metal casing which, by the Underwriters7 rules, has to be grounded. That produces a short circuit which may cause serious damage. To avoid that trouble, I provide a sheet-metal plating mounted L on the porcelain core and insulated thereby which encloses the exposed coil but is also open at top and bottom. This plating is inside of the regular casing and outside the coils, so that a break in the coil as above described will keep it from 'coming in contact with the grounded casing. Since the plating is insulated no external damage can occur.

Other features of my device will be described hereinafter.

Referring to the drawing, the usual porcelain core, (which may, however, be of any suitable insulating material), is shown at l with the customary helical groove Jr'ormed in its outer surface in which the coil is laid. This core is ordinarily made in sections bolted together by a central rod D. In this case l make the end sect-ions of hexagonal instead of circular outline and form thereon a projecting flange H and a seating base or shoulder h for the guard plating to be hereinafter explained. The said end sections are provided with outside bosses E, E for the circuit terminals of the coil, both of those terminals being usually at the same end of the core. The coil itself is shown at T. The aforesaid HEATER 1924. Serial No. 701,387.

guard-plating is formed in two parts R, R, i

two halves of the plating are spaced apart at si top and bottom to form top and bottom slots K and are secured together by screw-bolts J. The guard-plating is spaced an adequate distance from the heater coils-say half an inch more or less wider. The flanges H keep the plating from moving endwise and the hexagonal seat keeps it from rotating on the porcelain. The heater herein shown for illustration is of the `cross-seat form, being supported from the angle-rails B, B of the seat frame by a casing A which is perforated except along the two bottom strips beneath the two respective heater coils, to which strips the porcelain cores are secured by end brackets F, F. The ends S, S of the casing are spaced away from the coil end to form a junction-chamber for convenient connection of the wires which enter the casing in conduits through the knockout panels M, M. Over the heater and outside of the plating is extended a polished re- Hector-plate L, of aluminum or other suitable material. This plate protects the seat from undue heating by deflecting the heat downward and also diverts the convection currents outward through the perfor-ations in the casing. By removing this deiiector plate, which may be made in two parts if desired, convenient access to the junction chambers is had whi le the whole heater may be passed upward or downward between the seat rails B, B without disturbing the casing A. By the foregoing construction this breakage of a coil will cause no damage; it will merely unwind far enough to strike the guard-plating R, B, which is insulated by its mounting on the porcelain from the grounded casing A. Moreover, the plating eHectiv-ely prevents contact with the coil, by a metal umbrella-rod or other foreign obj ect which might be inserted through the perforations in the casing. The top and bottom slots of the guard-plating permit air currents to pass through in direct contact with the coils, while it itself takes the radiant component of the heat and is exand the slots K are somewhat posed on the outside to air currents within the casing.

What I claim as new and desire to secure by Letters Patent is:

5 1. AAn electric heater comprising a casing provided with an internal insulating support, an exposed coil heater mounted on said support and located within said casing, and an insulated two-part metallic guard plate l0 spaced from .said heater and the two parts of said guard plating spaced from each other so as to provide openings for air currents to pass through in -direct contact with the coil heater.

5 2. An exposed-coil heater having a coil mounted on an insulating support, an insulated two-part metallic guard-plating spaced from 'said coils 'and the two' parts spaced from each other and an external 'casing spaced go' from and insulated 'from said plating.

3. An exposed-coil heater having its coils mounted on an insulating support with pro- .truding ends, a twof-part metallic guard-plating embracing and insulate-d by said ends 25 with its two` parts spaced from each other and from the coil to provide air circulation and an external casing spaced from and insulated from the said guard-'plating by said insulating support, a plurality yof the walls of said 30 casing lying adjacent to said insulating support and approximately parallel therewith.

4. An exposed-coil heater having a coil mounted on an insulating support, a guardplating insulated from and spaced from said coil, an external casing spaced 'from and insulated from the plating and a heat deflector outside of the plating.

Signed at Albany, county of Albany and State of New York, this '20th day of March,

o 1924. y Y

LEE P. HYNES. 

